Rotary-brill pipe anb connecting means therefor



l A. SMITH. ROTARY DRlLL vPIPE AND CONNECTING MEANS THEREFOR.

APPLICATION FILED FEB. 5. 1916.'v

n a W E AV w Putvntod Nox'. 4, 191).

2 SHEETS-SHEET 2.

ANDREW SMEITH, OF SAN MATEO, CALIFORNIA, ASSIGNOR. TO SMITH METAL PEB,- IEORA'JIN'G- COMPANY' OF SAN' MATEO, CALIFORNIA.

` ROTARY-DRILL PIPE AND coNNEcTING MEANS rHEnEron weones.

ASpecification of Letters Patent.

' )Patented Nov. a, 1919.

Application filed February 5, S1916. Serial No. 76,365.

` To all whom it may concern.'

` tary table.

Iwhich are employed in drillin Be it known that I, ANDREW SMITH, a citizen of the 'United States, residing at San Mateo, in the county of Sian Mateo and State of California, have invented certain new and useful Improvements in Rotary- Drill Pipes and Connecting Means Therefor, of. which the following is a specificatlon..

This invention relates tothe construction of drill stems and connecting means for uniting the several sections or units thereof wells for oil, gas, and water and are especlally vadapted for use with rotary drilling rigs.'

In the loperation of drilling wells with a `rotary equipment it is the common practice to attach the cutter or drill bit by a threaded `or other connection to the lower end of a' drill stem consisting of connected sections of pipe, thetop section orv driving-stem .section being ,engaged by the rotary table which 1mparts the rotary motion. The driving-stem sections in use are .sometimes circular in made of special lshapes which may be-more readily held by the driving means of the ro- This driving. section is from twenty to fifty feetin length 'so that the dr1ll stem or pipe which depends from 1ts lower end may be lowered nearly that distance as it isrotated in forcing the dr1ll downward. When the drilling" hasproceeded until the driving sectionhas moved down -until its upperv end is nearly `level with the upperv surface of the turn table, it is necessary toy stop the rotation of the table, lift the entire' l length of stem sufficiently to disconnect the driving section, insert a new len th of pipe or unitviand then reatta'ch the.' riving section in order't'o proceed with the vdrilling operation. j

At the upper end of the drill stem there 1s connected a hydraulic swivel attached to a hose through which rwater is constantly forced down .the hollow stem, and passlng outwardly at the bottom through vents adjacent the drill'bitto wash away the drillings or detritus and ycarry them upwardly between the outside of the `d'rlll stem and the wall ofthe bore to the surface of the well.k v.

lt is customary to unite the ends of the .sections or. units ofv thedrillpipe or stem with union members or collarsthat are p rovided with fine cut threads slightlyl Haring to correspond with thetapered threads cut l in the ends of the pipe and when these connecting threads become very tightly screwed v'together during thedrilling operation they must undergo frequent.v screwing and -unf screwing during thev` drilling operation. In addition to the objections above mentioned, it has been found in practice that pipe sec tions which are threaded into-couplings do not properly aline when screwed together, and this results'in the formationv of bends at ythe joints which are thereby subjected to increased strains during the drilling operations frequently causing a breakage at those points. One of the purposes of my inventionl is to eliminate the use of couplings of this type in which the drill pipe or stem sections are threaded intothe connecting {ittingsf v During the drilling of a well it is very often necessary to lift the entire length of drill stem out of the well for thepurpose of replacing a' dull bit with a` sharp'one and `for *variousl other reasons familiar'to engineers ln this case the sections or units are sometimes unscrewed successively one by one' as theyl emerge from the well, but it is usual to suspend the pipe vfrom a high derrick erected over the well, and disconnect in about eighty foot lengths. To facilitate the vready removal of such lengths, it has been y'customary to insert a special two-part coupling at every third` or 'fourth joint` and spaced therefore, ab.out eighty feet apart, in which the opposite pin and socket portions are corresepondingly tapered and provided with heavy coarse threads.. While the coarse threads of these tapered couplingl members facilitate the operation of connecting and disconnecting the sections of a drill stem, greatly reducing the time and labor required and minimized the wearof the interlocking parts, yet the joints were weak and inadequate tosustain the enormous Weight and strains imposed because it vvas still necessary to use ne cut threads-on the ends ofthe pipe sections in securing the pin and socket portions thereon. Moreover, in order to have the .Walls of the coupling of adequate thickness for strength, it Was necessary to make the parts of such a diameter that they projected considerably beyond the outside Wall. of thedrill stem. The projections thus formed are-objectionable because f they form shoulders or threads 4, 6a.

abutments which rub against or drag upon the Wall of the Well, thereby breaking off soil along the sides of the Well, `causing it .to cave in and also forming 'a lodgin place for such falling material 'which inter eres with the removal vof the stem` when this becomes necessary.

One ofgthe main purposes of my invention is "to eliminate the use of inethreaded coupling membersf and the necessity forv threading the -ends of the pipe'sections and Ato unite the sections by means of strong coarse' threads vvhich are interlocked 'throughout their length by a minimum of turns or revolutions and may be constructed, of harder .material than the body of the pipe sections.

In the accompanyingdravvings, Figures 1 and 2 are fragmentary longitudinal sections of a coupling member attached to 'the ends of adjacent drill stem sections and embodying my invention, the pinl and socket portions of the coupling being disconnected and separated Fig. 1, and connected in Fig. 2; Fig, 3 1s Aa side elevation,

Awith the ends in sectlon, of a square drilling stem suitable for use 1n rotary machines and .called the grief pipe, Aembodying my invention and having the' pin and socket portions of the /coupling member or box connected to'opposite ends respectively; Fig. 4 is a side elevation partly insection vof a modification of my invention; Fig. .5 is a cross sectional view of the same; Fig. 6 is a side elevation, partly in section, of a rotary' drilling machine ofthe type used in the 011 elds of California and showing in longitudinal section a further modification of my dri1l`stem; and Fig. 7 is a crosssection on the line 7-7- of Fig( 6.

Referring to Figs.y 1, 2 and 3, the opposite ends of each section of my drill stem are provided respectivelyv with coupling members comprising a pin4 portion 4, and a socket portion 6, Whichare correspondingly tapered and provided with strong coarse The taper is such that the pin may be inserted nearly its full length before engagement with the socket and then a few turns or revolutions will completely `interlock the threads and will also seat the pin-shoulder 4b against the end Wall 6h of the socket, therebyl preventing the Wedging action upon the threaded partsV which v'v'ould otherwise occur. As appears from Fig. 2, the'pin is preferably shorter than v the pin'and socket the socket so that any .Wear may be compensated by cutting the shoulder4b permitting the pin to enter slightly, more into the socket; S

In order to eectively resist'the strains to which the threads are subjected by the Weight 0f the stem and due to the .torsional back and stresses of the drilling operation, I prefer to construct the end coupling elements of harder material than the body of the .pipe or stem and thenweld unite .it tothe latte-r in any suitable manner ,but preferably by one of the electric Welding processes. In some cases Ioind 'it also desirable to make members of diderent de'- grees of hardness, there being less' Wear upon the threads when one part is harder than the other. By my method of forming the pin and socket, portions of the coupling members separately yand of metal of any desired hardness and then Weld unite them the units vorsections I am enabled toI make to the ends of the stem or pipe sections'.

The parts maybe Welded by any suitable Welding process,` preferably by one of the electric Welding processes, preparing the adjacent parts -depending somewhat upon the particular method of welding employed. I have indicated by the merging of the light and 'heavy -cross.-. hatching at the ends, that the metal of the pipe and of the pin member have been united.' When the parts havebeenuthus Welded together, each unit or section of the stem isy complete vin elements forming an integral part thereof, the union between-the body of the pipe or the manner of j itself, the coupling stem and the end coupling elements being at least as strong as any other part. The lunits or sections may, therefore, be coupled together one after the other Without the necessity for any separate unions and can be lreadily connected and disconnected 'as often as required integrity of the coarse threads.

The main body of the stem may be al plain cylindrical pipe, corrugations not only ustrengt of the pipe against `Ncrushing strains but also increasing the lateral flexibility, i of bending which enables the pipe'to follow a bore that to which they would otherwise be subjected.. I prefer to `reinforce the stem at the lovver end adjacent the pin member as in? dicated ,at 8 in Figs. 6 and 7, .Where the stem is grasped by the tongs in connecting Without endangering the or corrugated, the lncreasing thel deviates' from a straight i course and relieves the joints of the strains thereby permitting a certain amount y It will be observed that the exterior diameter ofthe end coupling elements do not extend beyond the periphery of the main body of the pipe so that there are no projections extending beyond the outer wall of the pipe, and consequently there are no abutments to rub against and cut into the wall of the well or upon which caving material may lodge.

Circular stems are objectionable because of the difficulty 0f obtaining a grip in the driving mechanism of the rotary turn table.

I have therefore devised suitable shapes for' the drive stem section which can be easily manufactured and may be rmly held by the driving means. In Fig. 3, I have shown a square or rectangular stem and in Figs. 4 to 7 I have shown various fluted shapes, the grooves, recesses or corrugations extending longitudinally and terminating adjacent the end pin and socket coupling elements, the latter projecting over the grooves and forming shoulders 6 against which the elevators of the hoisting apparatus may engage, as illustrated in Fig. 6. The elevators may have bearing blocks 18 properly shaped to fit into the grooves in the stem and carrying pivot pins or trunnions 21 for the bail 19. It will be apparent that the rotary table may be easily supplied with driving members conforming to the shape of any of these stems and that their angular shapes will prevent any rotary slipping while allowing the stem to feed longitudinally as the drilling progresses.

The shape or configuration of the drive lstem section may be formed by rolling or by' means of dies while the metal is in the sheet, or by reshaping cylindrical tubes. In some cases it may be desirable to shape the stem from a solid billet and then bore a hole longitudinally therethrough.

In Figs. 4 and 5, I have shown the reinforcement 81 of circular section having its outer perimeter engaging the inner wall of the grooved portions of the stem.

lVhile I have described in detail the constructions illustrated in the accompanying drawings 'for the purpose of clearly disclosing my invention, it will be apparent to cnginecrs that various changes and modifications can be made within the scope of my claims and without departing from the spirit of my invention.

The many advantages which accrue from the improvements above described will be appreciated especially by those who have had experience in operating well drilling machinery. I have eliminated the necessity for auxiliary union members or fittings and have overcome the inherent defects in attached coupling members dueto the use of too many and too fine threads which were required when the ends of the pipe were threaded. My method of first forming the coarse taper threaded coupling elements and then weld uniting them to the tube or stem body not only eliminates the weaknessdue to thc fine cut threads heretofore employed but enables me to form the coupling el'ements of metal having a different hardness 'from the pipe, and if desired each element of a different degree of hardness, which diminishes the wear upon the threads. Moreover the weld union between the parts is at least as strong as any other part while the reinforcement of the parts that are gripped by the tongs and by the rotary machine insures the integrity of the stem under all circumstances and greatly increases its life. Furthermore, as above pointed out, my manner of constructing the units or sections of the stem overcomes the difficulties heretofore encountered by reason of the projections or abutments at the couplings, and the faulty alinement causing crooked drill stems.

I claim:

l. A drill stem unit or section, comprising a tubular metal casing having a weld-united coupling element at each end, one element having a coarsely threaded, tapering pin and the other element having a correspondingly flaring, coarsely threaded bore forming a socket, the casing adjacent the socket element having a reinforcement welded to said element.

2. A drill stem unit or section, comprising a tubular metal easing having a weld-united coupling element at each end, one element having a coarsely threaded, tapering pin and the other element having a correspondingly flaring, coarsely threaded bore formp ing a socket, the outer wall of said casing being substantially flush with the periphery of said elements at certain points and within said periphery between said points, whereby the periphery of said elements overhangs the walls of the casing at certain portions forming shoulders adapted to receive hoisting mechanism by which the drill stem may be lifted from a Well. v I

3. A drill stem unit or section, comprising a tubular metal casing having integral metal coupling elements at each end one of said elements being of harder material than the other.

4. A drill stem unit or section, comprising a tubular metal casing having integral coupling elements at each end, said elements having a substantially circular perimeter and said casing having a different sectional outline flush therewith at certain points and within the perimeter at the other points.

5. A drill stein unit or section, comprising a tubular metal casing having integral coupling elements at each end, said elements having a substantially circular perimeter .and said casing having a different sectional ments will overhang` certain portions of the wall of said casing thereby forming shoulders adapted to receive hoisting devices by@ which the ldrill stem may be lifted from a well. A

6. A section of a well-boring tube or pipe having at opposite ends mating 'coupling members integrally united with the walls of the tube and the exterior perimeter of the two being substantially flush with the periphery of the coupling members at certain points and within the periphery at the other points thereof, said coupling members comprising respectively a tapered externally coarsely screw-threaded pin, and a correspondingly internally conically flared and coarsely-threaded socket, so that the pipe sections may be readily connected to form a continuous stem of any l desired length and having an unobstructed exterior surface, by screwing the pin member of one section into the socket member of the preceding section, and so that the sections may be readily discolpected as the stem is withdrawn from a we 7. A drill stem unit or section, comprising a tubular metal casing having mating coupling elements at opposite ends, one ele ment comprising a coarsely threaded tapers ing pin and the other element comprising a correspondingly Haring coarsely threaded socket, said'coupling elements being formed of harder material than the .casing and being Welded thereto to thereby form the casing and coupling elements into an integral structure.

In testimony whereof I affix my signature in presence o two witnesses.l

ANDREW SMITH. Witnesses:

Ross M. HALLORAN, BEssm E. MUNRo. 

